Vertical distribution and species coexistence of mosquitoes inhabiting a deciduous forest in southern Louisiana were determined using 470 ml black jars for larval collections at ground level and 1, 3, 5, 7 and 9 m on selected trees. Specific preferences for discrete microhabitats by Aedes triseriatus, Ae. hendersoni, Ae. vexans and Ae. albopictus were not evident. Niche overlap indices, however, showed little overlap of these species and seemed to indicate that the mosquitoes partitioned the ovipositional/larval sites. Competition between the most abundant species, Ae. triseriatus and Ae. albopictus, was not apparent. The tree hole mosquito community structure appeared to be mediated by the predator, Toxorhynchites rutilus septentrionalis.